1. Field of the Invention
The preferred embodiments of the present invention relate, inter alia, to a cable handling structure for handling cables in a linear axis having a linearly movable member, and also relate to a substrate transfer device equipped with the cable handling structure.
2. Description of the Related Art
The following description sets forth the inventor's knowledge of related art and problems therein and should not be construed as an admission of knowledge in the prior art.
In some conventional transfer devices, a linear axis is employed for a movable portion. An example of such a transfer device equipped with a linear axis is disclosed by Japanese Unexamined Laid-open Patent Publication No. 2005-93812 (hereinafter referred to as “Document 1”). Document 1 describes that a holding arm for holding a substrate, such as, e.g., a wafer, is moved by a linear axis mechanism in a linearly slidable manner (see FIG. 8 of Document 1).
As a cable handling structure for appropriately guiding cables and/or tubes, such as, e.g., cables for supplying electric power or tubes for supplying fluid such as air or cooling water (hereinafter simply referred to as “cable(s)” in this disclosure including the specification, claims and abstract), between relatively movable two portions, a cable guide or a tube guide (hereinafter simply referred to as “cable guide” in the disclosure) is used. Such a cable guide is arranged along the linear axis with cables accommodated therein so as to guide the cables while being curved in a U-shaped manner. Such a guide has been conventionally used in various devices (see, e.g., Japanese Unexamined Laid-open Patent Publication No. H11-122790 (hereinafter referred to as “Document 2”)).
FIG. 9 is a cross-sectional view of a transfer device as seen from the axial direction of the linear axis in which cables for the linear axis of the transfer device as shown in Document 1 are handled by cable guides. In FIG. 9, the transfer device has two linear axes arranged in parallel with each other.
Two linear guide mounting plates 33 and 33 are arranged in parallel with each other at a distance and fixed perpendicularly to the base table 34. Linear guides 31 are fixed to the respective vertical outer surfaces of the linear guide mounting plates 33. Slidably mounted on the linear guides 31 and 31 are linear guide movable portions 32 and 32 to which basal ends of hands 27a and 27b are fixed respectively. Each linear guide 31 is arranged so as to extend in the depth direction in FIG. 9, so that the linear guide movable portion 32 is guided linearly while sliding on the linear guide 31. Thus, the depth direction in FIG. 9 is the moving direction of the linear axis of this transfer device. Each of the two hands 27a and 27b is configured to mount a wafer 28. The hands 27a and 27b are independently driven with motors (not shown) in the depth direction in FIG. 9, respectively, to transfer the wafers 28.
In the case of making the hand 27a and 27b hold a wafer 28 or electrically detecting the existence or nonexistence of a wafer 28, it is required to supply electric power or air to the hand 27a and 27b, which in turn necessitates some structure for guiding cables for supplying electric power or air to the hand 27a and 27b. In the embodiment shown in FIG. 9, the cable guide 38 for handling the cables is arranged along the linear axis and disposed in a U-shaped manner in the axial direction of the linear axis. One end of the cable guide 38 is fixed to the table 34 with the cable guide fixed side member 39, and the other end thereof is fixed to the basal end portion of the hand 27a and 27b via the cable guide movable side support post 40. Cables (not shown) are extended from the base 34 side to each cable guide 38 and accommodated in each cable guide 38, so that electric power or fluid (e.g., air) is supplied to the hand 27a and 27b. 
With this structure, in accordance with the movement of the hand 27a and 27b along the linear axis, the other end of the cable guide 38 is moved, which enables the cables accommodated in the cable guide 38 to be appropriately guided without causing any interference with other members.
In the linear axis as mentioned above, in cases where the cable guides 38 are arranged as shown in FIG. 9, if the bend radius of the U-shaped portion of each cable guide 38 is large, a large gap 42 will be required above the linear axis, which in turn increases the height size of the transfer device.
Furthermore, in the case of arranging two linear axes in parallel, a space for accommodating two cable handling structures will be required, which increases the width size of the transfer device.
For the purpose of reducing the device height, even if the cable guides 38 are arranged outside the linear axes as shown in FIG. 10, the planar size of the device increases.
In cases where a plurality of linear axes are arranged in parallel, the device size markedly increases by the aforementioned problems and that the arrangement of the cable guides becomes complicated.
The description herein of advantages and disadvantages of various features, embodiments, methods, and apparatus disclosed in other publications is in no way intended to limit the present invention. Indeed, certain features of the invention may be capable of overcoming certain disadvantages, while still retaining some or all of the features, embodiments, methods, and apparatuses disclosed therein.